Sustainable Plant and Animal Production

published in: 2022 - 2021 - 2020 - 2019 - 2018 - 2017 - 2016


Immunomodulatory effects of docosahexaenoic acid (DHA) in common carp

Nguyen TM, Tran Thi NT, Nguyen TH, Do TNA, Kestemont P. 2023. Immunomodulatory effects of graded levels of docosahexaenoic acid (DHA) in common carp (Cyprinus carpio) – In vitro and in vivo approaches. Fish & Shellfish Immunology 134:108585. DOI: 10.1016/j.fsi.2023.108585.

Resolvins work as anti-inflammatory mediators and are also called the immunomodulators in immune system that have potent multilevel mechanisms of action in disease models and promote resolution in animal models. D-series resolvins (such as DHA) play potent anti-inflammatory roles such as activating factors that reduce inflammation and blocking pro-inflammatory responses. The results of thi study suggest that docosahexaenoic acid is able to modulate an acute inflammation in immune cells by modifying the expression of key genes, with the DHA treatment at a dose of 75 μM/mL inducing the highest anti-inflammatory response. The dietary supplementation of DHA did not influence fish growth and feed utilization in the in vivo model; however, positive effects in immune responses and pathogenic resistance were observed in fish fed a diet supplemented with DHA at 20 g/kg of feed.


Plant extracts for striped catfish

Nhu PN, Hang BTB, Phuong NT, Kestemont P, Huong DTT. 2022. Effects of plant extracts on selected haematological parameters, digestive enzymes, and growth performance of striped catfish, Pangasianodon hypophthalmus (Sauvage, 1878) fingerlings. AACL Bioflux 15:1790–1806.

This study examined the effects of dietary supplementation with selected plant extracts on the haematology, enzymatic activities, and growth of striped catfish fingerlings. The enhancement of haematological parameters in conjunction with increased digestive enzyme activity may contribute to the improved health of catfish following the intake of a diet supplemented with plant extracts at different doses and feeding durations. A diet including Psidium guajava 0.2 and Phyllanthus amarus 0.2 extracts administered for 60 days has the potential to modify hematology, enzymatic activity as well as the growth of P. hypophthalmus. Hence, the preference of fish for various plant extract-based diets should be assessed, as these results could demonstrate high use and intake of aquafeed which may lead to improve growth performance of fish.

Immune responses and acute inflammation in common carp

Nguyen TM, Agbohessou PS, Nguyen TH, Tran Thi NT, Kestemont P. 2022. Immune responses and acute inflammation in common carp Cyprinus carpio injected by E.coli lipopolysaccharide (LPS) as affected by dietary oils. Fish & Shellfish Immunology 122:1–12. DOI: 10.1016/j.fsi.2022.01.006.

Eicosanoids, resolvins, and lipoxins formed from long-chain polyunsaturated fatty acids (LC-PUFAs) are the main lipid mediators in the inflammatory processes explaining the influence of dietary lipid sources on the immune system. This study aimed to determine the effects of dietary plant oils instead of fish oil or LC-PUFA supplementation in these oils on fish immune and inflammatory responses under normal and LPS-stimulated conditions. The use of plant oil did not cause any negative effects on fish growth, feed utilization, and survival. The supplementation of LC-PUFAs in diet did not lead to any change in husbandry variables measured in common carp. LPS was able to stimulate the immune system as well as induce acute inflammation in common carp. The dietary lipid sources have modified the immune responses and some other physiological processes involved in acute inflammatory processes. The fish oil-based diet supported an increase of the pro-inflammatory responses while the plant oil mixture or LC-PUFA supplemented diets led to higher anti-inflammatory responses and cytoprotection.


Non-invasive determination of fish maturity

Roosta Z, Falahatkar B, Sajjadi M, Paknejad H, Mandiki SNM, Kestemont P. Comparative study on accuracy of mucosal estradiol-17β, testosterone and 11-ketotestosterone, for maturity, and cutaneous vitellogenin gene expression in goldfish (Carassius auratus). Journal of Fish Biology n/a. DOI: 10.1111/jfb.14963.

Providing a non-invasive procedure to track fish maturity remains a priority in broodstocks' management. In the present study, the main goal was to assess reproduction status by measuring sex steroids and vitellogenin (VTG) in the skin mucosa, as a non-invasive method. For this purpose, the present study compared the levels of estradiol-17β (E2), testosterone (T), 11-ketotestosterone (11-KT), VTG and calcium (Ca) in skin mucosa and blood plasma of goldfish (Carassius auratus). Skin mucosal and blood samples were collected, as well as gonad tissues, from goldfish, as a seasonal spawner. The results show that measuring the mucosal androgens could be considered as an accurate, non-invasive method to monitor fish maturity.

Potential perception mechanisms for eliciting activities

Deboever E, Van Aubel G, Rondelli V, Koutsioubas A, Mathelie-Guinlet M, Dufrene YF, Ongena M, Lins L, Van Cutsem P, Fauconnier M-L, Deleu M. Modulation of plant plasma membrane structure by exogenous fatty acid hydroperoxide is a potential perception mechanism for their eliciting activity. Plant, Cell & Environment n/a. DOI: 10.1111/pce.14239.

Oxylipins are lipid-derived molecules that are ubiquitous in eukaryotes and whose functions in plant physiology have been widely reported. They appear to play a major role in plant immunity by orchestrating reactive oxygen species (ROS) and hormone-dependent signalling pathways. The present work focuses on the specific case of fatty acid hydroperoxides (HPOs). Although some studies report their potential use as exogenous biocontrol agents for plant protection, evaluation of their efficiency in planta is lacking and no information is available about their mechanism of action. In this study, the potential of two plant defence elicitors and the underlying mechanism of action is investigated. Arabidopsis thaliana leaf resistance to Botrytis cinerea was observed after root application with HPOs. They also activate early immunity-related defence responses, like ROS. As previous studies have demonstrated their ability to interact with plant plasma membranes (PPM), we have further investigated the effects of HPOs on biomimetic PPM structure using complementary biophysics tools. Results show that HPO insertion into PPM impacts its global structure without solubilizing it. The relationship between biological assays and biophysical analysis suggests that lipid amphiphilic elicitors that directly act on membrane lipids might trigger early plant defence events.

Dipteran-based meal and Nile tilapia

Agbohessou PS, Mandiki SNM, Gougbédji A, Megido RC, Lima L-MW, Cornet V, Lambert J, Purcaro G, Francis F, Lalèyè PA, Kestemont P. 2021. Efficiency of fatty acid-enriched dipteran-based meal on husbandry, digestive activity and immunological responses of Nile tilapia Oreochromis niloticus juveniles. Aquaculture 545:737193. DOI: 10.1016/j.aquaculture.2021.737193.

This study aimed to compare the enrichment capacity of polyunsaturated fatty acids (PUFA) and the long chain polyunsaturated fatty acids (LC-PUFA) of two dipteran species, black soldier fly (BSF) - and a blowfly, Chrysomya putoria (CP), and to test its influence on growth, digestive activities and immune responses of Nile tilapia. The results showed a higher efficiency of LC-PUFA enrichment for CP larvae compared to BSF ones, and a CP larval-based diet balanced in PUFA and LC-PUFA resulted in a greater stimulation of the processes of nutrient utilization, and thus a greater growth capacity. In addition, an improved DHA content was observed in the muscles of fish fed with the CP/FOD larval meal compared to those fed with all other insect larval meals. Nevertheless, all types of dipteran larval meal were palatable to Nile tilapia and enriched fish muscles with EPA except those fed the BSF/VGD diet. In addition, all types of dipteran larval meal boosted the immune status regardless of species or dietary essential fatty acid quality. Further studies are needed to elucidate the potential beneficial effects of BSF or CP larval meal on pathogen resistance in Nile tilapia.

Diet and skeletal anomalies in pikeperch larvae

El Kertaoui N, Lund I, Betancor MB, Carpentier C, Montero D, Kestemont P. 2021. Dietary DHA and ARA level and ratio affect the occurrence of skeletal anomalies in pikeperch larvae (Sander lucioperca) through a regulation of immunity and stress related gene expression. Aquaculture 544:737060. DOI: 10.1016/j.aquaculture.2021.737060.

Pikeperch (Sander lucioperca) is of great potential for the expansion of the EU aquaculture industry. However, larval survival is low and skeletal anomalies frequent. Pikeperch larvae are very stress sensitive to lack or low levels of n-3 dietary essential long chain polyunsaturated fatty acids (LC-PUFA, n-3). This study investigated the effect of different dietary DHA and ARA levels and ratios on larval development and performance, digestive capacity, fatty acids composition, skeleton anomalies and molecular markers of oxidative stress status, stress response, fatty acid synthesis, eicosanoids synthesis, and bone development. The results suggest an antagonistic effect of ARA and DHA fatty acids on immune/stress response of pikeperch, and its influence on bone development and deformity occurrence.

Optimal rearing conditions for Atlantic salmon fry

Cornet V, Geay F, Erraud A, Mandiki SNM, Flamion E, Larondelle Y, Rollin X, Kestemont P. 2021. Modulations of lipid metabolism and development of the Atlantic salmon (Salmo salar) fry in response to egg-to-fry rearing conditions. Fish Physiology and Biochemistry. DOI: 10.1007/s10695-021-00959-0.

To maintain or restore wild salmon populations, artificial reproduction from wild salmon breeders is common. In nature, the survival rate of salmon embryo is extremely variable (0 to 90%, mostly between 2 and 35%) due to water conditions, pathogens, pollutants, prey, etc. Conversely, controlled conditions used in fish culture allow a high survival rate of fry at the emergent stage, which, however, may not be well adapted for life in nature. Here, three factors affecting the fitness and physiology of salmon fry at their emergence were tested against a semi-natural incubation method in river: the origin of water (river vs drilling), the type of support in the incubator (support matrix vs plastic sheets) and the type of incubators (Californian vs vertical trays). Fry incubated in vertical trays + river water were similar in growth and lipid composition to those in semi-natural incubators. Further, the support matrix improved fish growth, lipid consumption and distribution compared to fry on plastic sheets, leading to large amounts of several PUFAs which may increase adaptation to cold conditions. Drilling water with lower amounts of fine particles (provoking the clogging of eggs) improved the survival rate compared to river water. To conclude, using a substrate combined with drilling water in artificial incubators could increase fry fitness and its adaption to wild life.

Melatonin improves immunity in pike-perch

Baekelandt S, Cornet V, Mandiki SNM, Lambert J, Dubois M, Kestemont P. 2021. Ex vivo approach supports both direct and indirect actions of melatonin on immunity in pike-perch Sander lucioperca. Fish & Shellfish Immunology 112:143–150. DOI: 10.1016/j.fsi.2021.03.005.

High stocking densities in aquaculture lead to overcrowding and affect fish health increasing the risk of infections. The search for alternatives of antibiotics and vaccines are based on the improvement of immunocompetence of cultured fish species through the use of stimulants. The melatonin hormone (Mel), is a multifunctional molecule in vertebrates with potential immunomodulatory capacity. This study shows with ex-vivo experiments in Pike perch, that Mel, with or without combination of cortisol, influences the expression of a set of immunity-related genes in the main fish lymphoid organs, the head kidney and the spleen. These genes include genes encoding for pro-inflammatory proteins, acute-phase proteins, and key factors of the adaptive immune system. Thus, immunoenhancing properties of Mel was confirmed under basal immune conditions in teleosts, and a direct action of Mel on immune organs was demonstrated.

Get rid of fishmeal for a more sustainable aquaculture

Agbohessou PS, Mandiki SNM, Gougbédji A, Megido RC, Hossain MS, Jaeger PD, Larondelle Y, Francis F, Lalèyè PA, Kestemont P. Total replacement of fish meal by enriched-fatty acid Hermetia illucens meal did not substantially affect growth parameters or innate immune status and improved whole body biochemical quality of Nile tilapia juveniles. Aquaculture Nutrition n/a. DOI:

Millions of tons of fish produced and captured every year are not used for human food, but mainly to produce fishmeal (FM) and fish oil (FO). FM is used as a protein source in compound feeds for many fish species in aquaculture, but its quantity and access are limited. The research group of Patrick Kestemont (URBE) is continuously searching for valuable alternatives to help preserve natural resources and render aquaculture more sustainable. One protein source could stem from insect larval meal, mixed with vegetable oil. This study investigates black soldier fly (BSF) larval meal enriched with fatty acids (FAs) on the growth and innate immune status of Nile tilapia juveniles. The results demonstrate that BSF meal can totally replace FM without substantial negative effects.

Rainbow trout and rapeseed oil diet

Gesto M, Madsen L, Andersen NR, El Kertaoui N, Kestemont P, Jokumsen A, Lund I. 2021. Early performance, stress- and disease-sensitivity in rainbow trout fry (Oncorhynchus mykiss) after total dietary replacement of fish oil with rapeseed oil. Effects of EPA and DHA supplementation. Aquaculture 536:736446. DOI: 10.1016/j.aquaculture.2021.736446.

Different vegetable oils (VO) have been investigated as potential substitutes of fish oil (FO) in aquaculture feed and several of them have proven to be successful in terms of fish growth rates, survival rates, biometric indices or feeding efficiency, even when used as the only oils in the feed. The aim of this study was to evaluate the effects of a 100% FO oil substitution by rapeseed oil on rainbow trout fry performance. Specifically, the objective was to test the effects of FO substitution on fish early growth and digestive metabolism, but also on the stress- and disease-resilience of the fish. Total replacement of FO by rapeseed oil in the feed did not compromise rainbow trout growth performance after an initial weaning period of several weeks, in spite of the altered fatty acid composition of the juveniles. Furthermore, fish fed VO-based diets showed no large differences in their responses to mild acute and/or repeated stress when compared to fish fed a control, FO-based commercial diet. Dietary rapeseed oil inclusion had, in contrast, important deleterious effects on the ability of fish to survive infection challenges.


COS-OGA Elicitation in Tomato

Moreau S, van Aubel G, Janky R, Van Cutsem P. 2020. Chloroplast Electron Chain, ROS Production, and Redox Homeostasis Are Modulated by COS-OGA Elicitation in Tomato (Solanum lycopersicum) Leaves. Frontiers in Plant Science 11. DOI: 10.3389/fpls.2020.597589.

Elicitation of plant cells induces a whole array of cytoplasmic and nuclear defense responses, a topic currently subject to particular attention by plant pathologists. Here, the effect of repeated elicitations of tomato by the COS-OGA elicitor was studied. Tomato plants were treated three times with the elicitor and compared their transcriptomes to control plants using RNA-Seq. It was shown that the response to the COS-OGA elicitor involved the modulation of the electron transport chain in thylakoids and impacted the redox homeostasis of different cell compartments including the apoplast. Therefore, beyond its protective effect against biotic stresses, the elicitation appears to be a major modulator of energy partitioning in plant leaves and repeated COS-OGA treatments most probably induce a long-term acclimation of plants, without any metabolic cost in terms of fresh and dry weights.

Plant oils for carp immunity

Nguyen TM, Mandiki SNM, Salomon JMAJ, Baruti JB, Thi NTT, Nguyen TH, Nhu TQ, Kestemont P. 2021. Pro- and anti-inflammatory responses of common carp Cyprinus carpio head kidney leukocytes to E.coli LPS as modified by different dietary plant oils. Developmental & Comparative Immunology 114:103828. DOI: 10.1016/j.dci.2020.103828.

To fight injuries or microbial infections, inflammation processes are launched. The inflammatory pathway involves many components including inducers, sensors and mediators. N-3 long chain polyunsaturated fatty acids (LC-PUFAs) play an important role in fish immune systems in particular and in animals more generally, and their imbalance or inadequate supply could lead to negative effects on fish health. The LC-PUFAs such as ARA, EPA, and DHA in fish diets are mainly provided by fish oil, which is however, very expensive. Plant-derived oils are much more available and cheaper. This study investigated how to maximise the utilisation of dietary plant oil for an efficient inflammatory response in common carp. The results indicate that the immune competence of fish fed plant oil mixture was comparable to the one of fish fed fish oil diet.

Plant oils for catfish immunity

Nhu TQ, Dam NP, Bich Hang BT, Bach LT, Thanh Huong DT, Buu Hue BT, Scippo M-L, Phuong NT, Quetin-Leclercq J, Kestemont P. 2020. Immunomodulatory potential of extracts, fractions and pure compounds from Phyllanthus amarus and Psidium guajava on striped catfish (Pangasianodon hypophthalmus) head kidney leukocytes. Fish & Shellfish Immunology 104:289–303. DOI: 10.1016/j.fsi.2020.05.051.

Due to the increasing demand for sustainable applications in aquaculture, plant-based natural sources are a promising source for medicinal discovery to strengthen fish immunity. Among plants of potential medical interest, guava (Psidium guajava) and bhumi amla (Phyllantus amarus) are known to possess pharmacological activities including anti-bacterial, anti-oxidant as well as immune response activities. Earlier studies only focused on the immunomodulatory effects of crude ethanol extracts of these plants. The present study now tries to identify the type of compound(s) which could contribute to this activity. The crude extracts were fractioned with increasing polarity solvents and separated into fractions containing different concentrations and types of bioactive compounds (from less polar to more polar compounds) and investigated using striped catfish head kidney leukocyte model. Hexane fractions of both plant extracts inhibited the viability of HKLs (head kidney leukocytes), while several other fractions enhanced the cell viability. All P. guajava fractions at all or some concentration considerably enhanced the respiratory burst assay production in HKLs. Similarly, nitric oxide synthase production was also significantly increased by some or all concentrations of P. guajava dichloromethane and ethyl acetate fractions.

Plant diets for rainbow trout

Hossain MS, Chance AB, El Kertaoui N, Wattiez X, Houndji A, Mandiki SNM, Kestemont P. Dietary inorganic monophosphates in high plant ingredient-based diets influence nutrient digestibility, postprandial macro-mineral status and immune functions of juvenile rainbow trout, Oncorhynchus mykiss. Aquaculture Nutrition n/a. DOI: 10.1111/anu.13156.

Inorganic monophosphates supplementation effects in high plant ingredient‐based diets of juvenile Oncorhynchus mykiss were evaluated by feeding four experimental diets supplemented with 11.4, 10.0, 11.5 and 10.0 g/kg of monocalcium phosphate (MCP), monoammonium phosphate (MAP), monopotassium phosphate (MKP) and monosodium phosphate (MSP), respectively. After 60 days, MAP and MKP supplemented groups showed improved growth and feed intake (p > .05). Apparent digestibility coefficient of dry matter (ADCDM) was significantly higher in MSP diet followed by MKP, MCP; MAP diet showed significantly lower ADCDM. MAP and MSP diets showed significantly higher mineral digestibility. The postprandial plasma P levels were significantly influenced by the dietary treatments and the period after a single meal. MAP, MKP and MSP groups showed significantly higher baseline P concentration than MCP. The other macro‐minerals (Ca, Mg, K and Na) were significantly influenced by the postprandial time. MSP and MKP diets showed significantly higher lysozyme activity. Total immunoglobulin was significantly higher in MSP group. MKP diet showed significantly higher expression of cd4‐2β genes compared with MCP. Significantly higher lysozyme gene expression observed in MSP diet followed by MKP; MAP and MCP groups showed significantly lower value. Finally, MAP, MKP and MSP significantly improved nutrient digestibility, mineral bioavailability and immune functions of rainbow trout compared with MCP in high plant ingredient‐based diets.

Traditional medicine in aquaculture

Nhu TQ, Bich Hang BT, Cornet V, Oger M, Bach LT, Anh Dao NL, Thanh Huong DT, Quetin-Leclercq J, Scippo M-L, Phuong NT, Kestemont P. 2020. Single or Combined Dietary Supply of Psidium guajava and Phyllanthus amarus Extracts Differentially Modulate Immune Responses and Liver Proteome in Striped Catfish (Pangasianodon hyphophthalmus). Frontiers in Immunology 11. DOI: 10.3389/fimmu.2020.00797.

In aquaculture, infectious pathogens (e.g., viruses, bacteria, parasites, and fungi) causing high mortality rates are a major problem leading to tremendous economic losses. Guava (Psidium guajava) and bhumi amla (Phyllanthus amarus), two well-known plants in traditional medicine were tested on their effects on immune responses, disease resistance and liver proteome profiles in striped catfish Pangasianodon hypophthalmus. The diets based on the plant extracts improved growth parameters as well as the cellular immune responses in spleen and the humoral immune responses in plasma. Fish mortality following bacterial infection was lower with single Pg and Pa extracts, and to lesser extent with combined extracts compared to a control group.

Plant oil diets for carps

Nguyen TM, Mandiki SNM, Gense C, Tran TNT, Nguyen TH, Kestemont P. 2020. A combined in vivo and in vitro approach to evaluate the influence of linseed oil or sesame oil and their combination on innate immune competence and eicosanoid metabolism processes in common carp (Cyprinus carpio). Developmental & Comparative Immunology 102:103488. DOI: 10.1016/j.dci.2019.103488

Fish oil for aquaculture comes from fish stock that are currently overexploited. Consequently, fish oil is very expensive. Plant oils, much cheaper, could serve as ideal alternative lipid sources for fish diets. This study uses pure or mixed linseed and sesame oil to test innate immune competence and eicosanoid metabolism in common carp (Cyprinus carpio). Results show that plant oils did not induce any negative effects on fish growth, survival, and immune competence status. When the oils were mixed, carps even utilised the food more efficiently and seemed more effective in inducing a better immunomodulatory response when exposed to lipopolysaccharides of Escherichia coli through a more active eicosanoid metabolism process.


2 x Plant extract-based diets for striped catfish

Nhu TQ, Bich Hang BT, Bach LT, Buu Hue BT, Quetin-Leclercq J, Scippo M-L, Phuong NT, Kestemont P. 2019. Plant extract-based diets differently modulate immune responses and resistance to bacterial infection in striped catfish (Pangasianodon hypophthalmus). Fish & Shellfish Immunology 92:913–924. DOI: 10.1016/j.fsi.2019.07.025.

Nhu TQ, Bich Hang BT, Vinikas A, Bach LT, Buu Hue BT, Thanh Huong DT, Quetin-Leclercq J, Scippo M-L, Phuong NT, Kestemont P. 2019. Screening of immuno-modulatory potential of different herbal plant extracts using striped catfish (Pangasianodon hypophthalmus) leukocyte-based in vitro tests. Fish & Shellfish Immunology 93:296–307. DOI: 10.1016/j.fsi.2019.07.064.

Striped catfish (Pangasius hypophthalmus) is one of the most important commercial fish species cultured in Vietnam. Yet, intensive production with high stocking densities increases mortality rates due to bacterial infections and cause enormous economic losses. The use of herbal immunostimulants in aquaculture would offer an environmentally friendly approach in disease management. Two studies – in vivo & in vitro - confirmed the positive effects of medicinal plant extracts by improving the immune response of striped catfish. Both, hematological parameters (total red blood cells, white blood cells, lymphocytes, monocytes, and neutrophils) and humoral immune responses (lysozyme, complement and total immunoglobulin) of fish fed with extract-based diets were significantly higher than of those fed with the control diet. Ethanol plant extracts stimulated striped catfish immune system by affecting peripheral blood mononuclear cells (PBMCs) and head kidney leukocytes (HKLs). The results offer an effective strategy to improve striped catfish health by enhancing their immune system, and to promote sustainable aquaculture.

Systemic defense activation in rice

Singh RR, Chinnasri B, De Smet L, Haeck A, Demeestere K, Van Cutsem P, Van Aubel G, Gheysen G, Kyndt T. 2019. Systemic defense activation by COS-OGA in rice against root-knot nematodes depends on stimulation of the phenylpropanoid pathway. Plant Physiology and Biochemistry. 142:202–210. DOI: 10.1016/j.plaphy.2019.07.003.

Infections with parasitic nematodes, e.g. the root-knot nematode (RKN), cause important agricultural losses in rice production. The conventional control of RKN with nematicides is challenging and not environmentally friendly. This study tests formulations of chitosan oligomers (COS) and pectin-derived oligogalacturonides (OGA), COS-OGA, for their potential and mode-of-action as preventive measures to control RKN Meloidogyne graminicola infection in rice. FytoSol® and FytoSave® applied to leaves 24h before nematode inoculation reduced root-galling and nematode development significantly, showing for the first time a systemic effect of these defence elicitors. The systemic defence activation is not correlated with defence hormone accumulation in the rice shoots and roots but dependent on the stimulation of the phenylpropanoid pathway.

Plant oil diets for common carp

Nguyen TM, Mandiki SNM, Tran TNT, Larondelle Y, Mellery J, Mignolet E, Cornet V, Flamion E, Kestemont P. 2019. Growth performance and immune status in common carp Cyprinus carpio as affected by plant oil-based diets complemented with β-glucan. Fish & Shellfish Immunology 92:288–299. DOI: 10.1016/j.fsi.2019.06.011.

A major constraint in the future of aquaculture is the limited availability of fish meal and fish oil. Alternative solutions to feed fish with plant products would be much cheaper and much more abundant. Most plant-derived oils contain polyunsaturated fatty acids (PUFA) but no long chain PUFAs (LC-PUFA, > 18C), that play an important role in fish (and human) health. Omnivorous fish species such as the common carp (Cyprinus carpio) are able to biosynthesise LC-PUFAs from plant oil PUFA precursors. This study compares the immunocompetence status of fish fed with fish- and plant oil. After bacterial infection, mortality rate did not differ. Thus, common carp fed plant oil-based diets are able to produce substantial amounts of LC-PUFA for sustaining growth rate, immune status and disease resistance similar to fish fed a fish oil-based diet.

Cloning and modelling of enzymes

Tinti E, Geay F, Lopes Rodrigues M, Kestemont P, Perpète EA, Michaux C. 2019. Molecular cloning and 3D model of a fatty-acid elongase in a carnivorous freshwater teleost, the European perch (Perca fluviatilis). 3 Biotech 9:242. DOI: 10.1007/s13205-019-1773-x.

The European perch (Perca fluviatilis) is a carnivorous freshwater fish able to metabolise polyunsaturated fatty acids (PUFA) into highly unsaturated fatty acids (HUFA), that are essential fatty acids for humans and animals. This makes it a potential candidate for sustainable aquaculture development, since input-intensive fish oil could be replaced by vegetable oil. This study investigates especially the fatty-acid elongase (ELOVL) family, one of the two enzymatic systems implied in the HUFA biosynthesis. To gain knowledge on its molecular structure, molecular cloning and 3D modelling approaches are applied.

The best diet for pikeperch larvae

El Kertaoui N, Lund I, Assogba H, Domínguez D, Izquierdo MS, Baekelandt S, Cornet V, Mandiki SNM, Montero D, Kestemont P. 2019. Key nutritional factors and interactions during larval development of pikeperch (Sander lucioperca). Scientific Reports 9:7074. DOI: 10.1038/s41598-019-43491-1.

Pikeperch as great potential for European aquaculture. However, nutritional requirements for freshwater species are yet not well understood. Following a fractional factorial experimental design, this study is a first attempt to evaluate the simultaneous effects of selected fatty acids, vitamins and minerals, in total, 8 nutritional variables to identify their respective importance and interactions in pikeperch larval development. Survival, growth rate, sekletal anomalies etc. were analysed. Essential elements in larval diet were Ca/P, long chain polyunsaturated fatty acids and vitamins (C & E).

Vegetable oils for catfish

Sourabié A, Mandiki SNM, Geay F, Ahoulé AG, Naert N, Toguyeni A, Kestemont P. Tropical Vegetable Oils Do Not Alter Growth Performance in African Catfish through a High n-6 Polyunsaturated Fatty Acids Biosynthesis Capacity. Lipids 0. DOI: 10.1002/lipd.12145.

Fish oil, usually used for fish nutrition in aquaculture, was completely replaced by vegetable oils to feed African catfish. This did not affect growth performance with the exception of Shea butter diet, where growth was lower. Other indicators (muscle arachidonic acid, gene expression in the liver) support the recommendation that fish oil could be replaced by desert date oil.

Pikeperch & salinity

Lund I, Rodríguez C, Izquierdo MS, El Kertaoui N, Kestemont P, Reis DB, Dominguez D, Pérez JA. 2019. Influence of salinity and linoleic or α-linolenic acid based diets on ontogenetic development and metabolism of unsaturated fatty acids in pike perch larvae (Sander lucioperca). Aquaculture 500:550–561. DOI: 10.1016/j.aquaculture.2018.10.061.

Pike perch farming predominantly takes place in freshwater. However, their osmotic tolerance in a saline environment may offer a growth potential for rearing this teleost fish in low saline waters. The study examines effects of fatty acids and salinity at low saline rearing conditions. A detailed evaluation of the different types of skeleton anomalies as well as the expression of related molecular markers was conducted for the first time in the larval phases of this species. One of several articles published within the project Diversify!

Pikeperch & Light

Baekelandt S, Mandiki SNM, Schmitz M, Kestemont P. 2019. Influence of the light spectrum on the daily rhythms of stress and humoral innate immune markers in pikeperch Sander lucioperca. Aquaculture 499:358–363. DOI: 10.1016/j.aquaculture.2018.09.046.

The culture of Pikeperch (Sander lucioperca) is still limited due to impaired growth and high mortality during the young developmental stages. Inadequate rearing conditions probably increase stress levels since aquaculture management has not been optimized yet. This study investigates the daily variations of stress markers (plasma cortisol and glucose and some humoral innate immune markers) and the effect of light spectrum on these variations.


Alternative soil amendments

Li, Z, Delvaux, B, Yans, J, Dufour, N, Houben, D, & Cornelis, J-T 2018, ‘Phytolith-rich biochar increases cotton biomass and silicon-mineralomass in a highly weathered soil’, Journal of Plant Nutrition and Soil Science, vol. 181, no. 4, pp. 537–546, doi: 10.1002/jpln.201800031

Non‐essential silicon (Si) is beneficial to plants by improving photosynthetic activity and alleviating stresses. Natural soil weathering and removal of harvested biomass leads to desilication. Si‐rich biomass (e.g. Miscanthus) can be transformed into biochar (= charcoal used as a soil amendment) to supply bioavailable Si. The authors show that Miscanthus biochar is an alternative Si amendment to supply bio-available Si, increase plant biomass, and promote the biological cycle of Si in the soil–plant system. The positive impact of a Si-rich biochar was larger in old, desilicated, highly-weathered Nitisol.

 Diets for pikeperch larvae

Lund, I, Kertaoui, NE, Izquierdo, MS, Dominguez, D, Hansen, BW, & Kestemont, P 2018, ‘The importance of phospholipids combined with long-chain PUFA in formulated diets for pikeperch (Sander lucioperca) larvae’, British Journal of Nutrition, vol. 120, no. 6, pp. 628–644, doi: 10.1017/S0007114518001794

Pikeperch (Sander lucioperca; also: zander) is considered one of the most valuable food fish native to Europe. This study aimed to determine optimal dietary levels of soyabean lecithin (SBL)-derived phospholipids (PL) in starter feeds for pikeperch larvae. Liver proteomic analyses, physiological expression and interactions in larval proteins, bone anomalies, digestive enzymatic activity, candidate gene expression and skeleton morphogenesis were examined. The supplementation of essential fatty acids had beneficial effects on pikeperch larvae development.

Possible alternatives to control blight disease in potatoes

van Aubel, G, Serderidis, S, Ivens, J, Clinkemaillie, A, Legrève, A, Hause, B and Van Cutsem, P 2018, Oligosaccharides successfully thwart hijacking of the salicylic acid pathway by Phytophthora infestans in potato leaves. Plant Pathology doi:10.1111/ppa.12908

Potato late blight (caused by Phytophthora infestans), the most important potato disease worldwide, requires massive amounts of fungicides. Stimulating the plant’s innate immunity opens ways to new biological plant protection tools such as elicitor molecules. This study shows that especially one elicitor oligosaccharide - FytoSol, a new composition still under development by the spin-off FytoFend - was efficient in controlling the diversion of late blight. It could become part of an integrated pest management strategy allowing for reduction of fungicide use and related environmental impact in potato fields.

Optimal aquaculture modalities for pikeperch

Baekelandt, S, Redivo, B, Mandiki, SNM, Bournonville, T, Houndji, A, Bernard, B, El Kertaoui, N, Schmitz, M, Fontaine, P, Gardeur, J-N, Ledoré, Y, & Kestemont, P 2018, ‘Multifactorial analyses revealed optimal aquaculture modalities improving husbandry fitness without clear effect on stress and immune status of pikeperch Sander lucioperca’, General and Comparative Endocrinology, vol. 258, pp. 194–204, doi: 10.1016/j.ygcen.2017.08.010

High mortality and impairment in growth rate during pikeperch (Sander lucioperca) ongrowing are among the major bottlenecks for its development in aquaculture. These failures may be related to high stress responsiveness since the rearing conditions are not yet optimized for this species. The objectives were to characterize the stress and immunological responses of pikeperch to major aquaculture modalities, and to identify the optimal aquaculture conditions for improving its welfare status.

Reproduction performances of pikeperch

Khendek, A, Chakraborty, A, Roche, J, Ledoré, Y, Personne, A, Policar, T, Żarski, D, Mandiki, R, Kestemont, P, Milla, S, & Fontaine, P 2018, ‘Rearing conditions and life history influence the progress of gametogenesis and reproduction performances in pikeperch males and females’, Animal, vol 12(11), pp. 2335-2346, DOI: 10.1017/S1751731118000010

Pikeperch (Sander lucioperca) is a highly valuable fish in Europe and could be a promising candidate for the development of aquaculture. However, its reproduction in the wild highly depends on the season demanding a controlled photothermal program for their domestication. This study investigated gametogenesis and reproduction of two groups of pikeperch with different life histories. Only those fish that had been exposed to natural changes in temperature/photoperiod conditions were able to spawn successfully.


Clinckemaillie A, Decroës A, van Aubel G, Santos SC dos, Renard ME, Van Cutsem P, Legrève A. 2017. The novel elicitor COS-OGA enhances potato resistance to late blight. Plant Pathology 66:818–825. DOI: 10.1111/ppa.12641.

Douxfils, J, Fierro-Castro, C, Mandiki, R, Emile, W, Tort, L & Kestemont, P 2017, 'Dietary β-glucans differentially modulate immune and stress-related gene expression in lymphoid organs from healthy and Aeromonas hydrophila-infected rainbow trout (Oncorhynchus mykiss)' Fish and Shellfish Immunology, vol 63, pp. 285-296. DOI: 10.1016/j.fsi.2017.02.027

Khendek, A, Alix, M, Viot, S, Ledoré, Y, Rousseau, C, Mandiki, R, Kestemont, P, Policar, T, Fontaine, P & Milla, S 2017, 'How does a domestication process modulate oogenesis and reproduction performance in Eurasian perch?' Aquaculture, vol 473, pp. 206-214. DOI: 10.1016/j.aquaculture.2017.02.003

Khuyen, TD, Mandiki, SNM, Cornet, V, Douxfils, J, Betoulle, S, Bossier, P, Reyes-López, FE, Tort, L & Kestemont, P 2017, 'Physiological and immune response of juvenile rainbow trout to dietary bovine lactoferrin' Fish & Shellfish Immunology, vol 71, pp 359-371. DOI: 10.1016/j.fsi.2017.10.027

Mandiki, R, Milla, S, Nkogo Robles, S & Kestemont, P 2017, 'Corticosteroids deeply depress the in vitro steroidogenic capacity of Eurasian perch ovary at the end of the reproductive cycle' General and Comparative Endocrinology, vol 245, pp. 44-54. DOI: 10.1016/j.ygcen.2017.02.002

Mellery, J, Brel, J, Dort, J, Geay, F, Kestemont, P, Francis, DS, Larondelle, Y & Rollin, X 2017, 'A n-3 PUFA depletion applied to rainbow trout fry (Oncorhynchus mykiss) does not modulate its subsequent lipid bioconversion capacity' British Journal of Nutrition, vol 117, no. 2, pp. 187–199. DOI: 10.1017/S0007114516004487

Mellery, J, Scalisi, F, Bonnineau, C, Kestemont, P, Rollin, X & Larondelle, Y 2017, 'Impact of lignans on the polyunsaturated fatty acid metabolic processing in a rainbow trout (Oncorhynchus mykiss) cell line' Aquaculture, vol 476, pp. 106-110. DOI: 10.1016/j.aquaculture.2017.04.022

Schmitz, M, Baekelandt, S, Bequet, S & Kestemont, P 2017, 'Chronic hyperosmotic stress inhibits renal Toll-Like Receptors expression in striped catfish (Pangasianodon hypophthalmus, Sauvage) exposed or not to bacterial infection' Developmental and Comparative Immunology, vol 73, pp. 139-143. DOI: 10.1016/j.dci.2017.03.020


Khuyen TD, Mandiki SNM, Douxfils J, Cornet V, De Schryver P, Bossier P, Betoulle S, Tort L, Kestemont P. 2016. Physiological and immune pathway responses of rainbow trout juveniles to dietary supplementation with inulin and lactoferrin. Fish & Shellfish Immunology 53:117. DOI: 10.1016/j.fsi.2016.04.101.

Mandiki SNM, Redivo B, Baekelandt S, Douxfils J, Lund I, Höglund E, Kestemont P. 2016. Long-term tryptophan supplementation decreased the welfare and innate immune status of pikeperch juveniles. Fish & Shellfish Immunology 53:113–114. DOI: 10.1016/j.fsi.2016.04.090.

Mellery, J, Geay, F, Tocher, DR, Kestemont, P, Debier, C, Rollin, X & Larondelle, Y 2016, 'Temperature increase negatively affects the fatty acid bioconversion capacity of rainbow trout (Oncorhynchus mykiss) fed a linseed oil-based diet' PLoS ONE, vol 11, no. 10, e0164478. DOI: 10.1371/journal.pone.0164478

Redivo B, Mandiki SNM, Bournonville T, Baekelandt S, Fontaine P, Ledoré Y, Kestemont P. 2016. Characterization of neurophysiological and immune responses of pikeperch juveniles to major stress factors under intensive culture conditions. Fish & Shellfish Immunology 53:72. DOI: 10.1016/j.fsi.2016.03.084.

Schmitz, M, Douxfils, J, Mandiki, R, Morana, C, Baekelandt, S & Kestemont, P 2016, 'Chronic hyperosmotic stress interferes with immune homeostasis in striped catfish (Pangasianodon hypophthalmus, S.) and leads to excessive inflammatory response during bacterial infection' Fish & shellfish immunology, vol 55, pp. 550-8. DOI: 10.1016/j.fsi.2016.06.031

van Aubel, G, Cambier, P, Dieu, M & Van Cutsem, P 2016, 'Plant immunity induced by COS-OGA elicitor is a cumulative process that involves salicylic acid' Plant Science, vol 247, pp. 60-70. DOI: 10.1016/j.plantsci.2016.03.005